Apparatus for nitrogen fixation



F. DARLINGTUN. APPARATUS FOR NITROGEN FIXATION.

- APPLICATION FILED NOV- 23, 19!].

3 SHEETSSHEET l- INVENTOR W270? flar/My/wz Patented Dec. 27, 1921.

WITNESSES: R gym ATT'ORNEY F. DARLINGTON. I APPARATUS FOR NITROGEN FIXATION.

APPLICATION FILED NOV- 23. I917.

Patented Dec. 27, 1921.

3 SHEETS-SHEET 2.

WITNESSES:

ATTORNEY F. DARLINGTON. APPARATUS FOR NITROGEN FIXATION. APPLICATION FILED NOV. 23, 1917.

Patented Dec. 27, 1921.

3 SHEETSSHEET 3.

WITNESSES:

' 2 AT'ILORNEY I I UNITED STATES PATENT OFFIOE.

FREDERICK DARLINGTON, OF NEW YORK, N. Y., ASSIGNOR TO WILSTINGHOUSE ELEG- TRIC & MANUFACTURING COMPANY,

A CORPORATION OF PENNSYLVANIA.

APPARATUS FOR NITROGEN FIXATION.

Application filed November 23, 1917. Serial No. 203,539.

To all whom it may concern:

Be it known that I, FREDERICK DARLING- TON, a citizen of the United States, and a-resident of New York city, in the county of New York and State of New York, have invented a new and useful Improvement in Apparatus for Nitrogen Fixation, of which the fol- 4 are detail views of portions of the apparatus employed in the furnace of Fig. 2; and Figs. 6 and 7 are detail views illustratlng certain portions of the apparatus em- I ployed in the furnace of Fig. 5.

Processes for the fixation of atmospheric nitrogen are well known in which a stream of nitrogen-bearing gas is passed over a mixture of carbon and alkali-metal carbonate in the presence of a catalyzing agent, such as iron, which serves to dissolve the carbon and thus break down the structure of the carbon molecules. Processes of this nature are fullyset forth and claimed in U. S. Patent No. 1,091,425, issued to the Nitrogen Products Company on March 24, 1914, on

an application filed by John 'E. Bucher.

In the process of the aforementioned Bucher patent,the carbon and alkali-metal carbonate are reduced to a finely divided state, thoroughly mixed, and then placed in a retort, together with an admixture of '.finely divided iron. -A nitrogen-bearing stream of gas being then passed over the mixture, the finely divided iron acts as,a

catalyzer, dissolving a portion of the carbon and reducing it substantially to the nascent state, whereupon thenitrogen combines therewith, forming cyanogen which immediately combines with the alkali metal set free by the reduction of the carbonate by the remainder of the carbon. This operation is very effective, particularly on asmall scale, but difiiculties are encountered,.

at times, in securing the proper relative amounts of nitrogen and of alkali-metal carbonate at each and every point where the reaction is taking place. Thus, if there is an excess of carbonate or if the temperature of the furnace is too high, the carbonate permeates the entire mass of the charge, preventing the entry of nitrogen thercinto and limiting the reaction to the outer surface of the mass. On the other hand, if there is a deficiency of alkali-metal carbonate, or if the temperature of the furnace be slightly too low, the fused carbonate does not penetrate through the mass of iron filings and carbon, and a large portion of the divided material is ineffective.

By the present process, I provide'means whereby a mixture of carbonate andcarbon'is continuously ground and mixed within a heated nitrogen-containing space by .a mechanism comprising grinding faces composed wholly or in part of iron. By this means, all portions of the reacting mass are continuously kept in motion and intimately mixed, and, furthermore, carbonized surfaces of iron are continuously being exposed to the nitrogen gas, whereby the reaction may be effected with substantially uniform results, even though there be wide variations in the amounts of the constituent reagents and in the temperature of the furnace.

Referring to the drawing for a more detailed understanding of .my invention, I show the barrel of a rotatable or tubular furnace, such as is commonly employed in cement manufacture, at 8, in Fig. 1. Said barrel comprises an outer supporting casing 9 provided with a heat-resistant lining 10 which, in turn, is provided with a lining 11, preferably assuming the form of a plurality of' iron rings 1212, each of which has a peripheral groove in its inner face.

The barrel 8 is mounted for rotation in a sloping position as by being placed uponrollers 13-13 and is driven by any suitable means, such, for example, as a motor 14 operating upon a girth gear 15.

The interior of the barrel 8 may be heated by any suitable means such, for example, as a flame of powdered coal 16, shown as issuin from a nozzle 17, the coal being supplied from a hopper 18 by a screw feed 19 and a suitable air blast being provided as by a blower 20. The products of com- A 55 be treatedjfor the removal of the sodium cybarrel 8 is turned by up a suitable flue 21.

A charge of alkali-metal carbonate and' 'powdered carbon isplaced in a hopper 22 and is supplied to the upper end of the barrel 8, as by a screw feed 23.

In order to supply the interior of the barrel 8. with nitrogen, in addition to that; issuing from the nozzle 17, air may be driven by a suitable blower 24 through a. mass of incandescent carbon 25 and into the furnace at 26,thus insuring an amplesupply of nitrogen for the furtherance of the reaction.- Y g In order to intimately grind and mix the charge and, at the sametime, topresent thereto large and constantly refreshed surfaces of catalytic material, I place balls 27-27 of ferrous material in the respective grooves of the rings 12-12 so that as the the motor 14, said balls roll in said grooves. n

. Having thus described an apparatus embodying my invention, the operation is as follows: The heating source 16 is placed in operation andthe barrel 8 is rotated until all portions thereof are thoroughly heated. The fan 24 is then started, forcing a1r through the mass of incandescent carbon at 25 and into the furnace. The effect of the carbon at 25 is to change the oxygen of the .air'into'either carbon monoxid or carbon di-oxid,"preferably the former. The feed permitted t slowly pass into the furnace,

. whence it passes from groove to groove untilr it falls from the barrel 8 into a pocket 28.

The rotation ofthe furnace barrel causes theballs 27 to continually traverse'their respective grooves andito thoroughly mix and grind the charge as it slowly passes through g the furnace. "The temperature is so-h gh. that the iron rings 12 and the balls 27 are capable of readily taking up carbon from the pharge. 'Said carbon, when dissolved ini iron, is rendered chemically, active. in its molecular structure and, in this form, readily "combines "with the nitrogen passing throughhthe furnace and with the sodium formed" by the reduction of the sodium car bonate: by a portionof thecarbon, forming sodium cyan1d,-'whichipasses' through the barreI S w the pocket 28, together with such v portions bfithe charge as arenot acted upon.

,tillat'ion,

employed to. fore demands-ho-furtheri verse the conductor 31 of the active grinding surfaces from the catlining 10. Within this lining is a layer 30 of insulating, heat-resistant material such,

for example, as mica or asbestos, Within which is embedded a heating conductor 31 which is wrapped around the entire length of the tube 8 and terminates in suitable slip rings 32-32 which are connected, in turn, by suitable brushes, to the terminals of a source of heating current such, for example, as the secondarywinding '33 of a transformer 34. r I

Mounted within the layer 30- are a plurality of iron rings 34-34, shown as pr0vid-. ed with substantially cylindricalinner surfaces. A plurality of rollers 35-35 are mounted to bear upon the inner surfaces of the rings 34-34 and said members 35 are preferably provided with pronounced helical grooves in their outer faces, as shown. The members 35 are loosely keyed to a shaft 36, as indicated in Fig. 4, and said shaft may be driven by a suitable motor37, preferably through a universal joint 38.

A nitrogen-bearing gas stream is intro- 'duced at 26, as in the furnace of Fig. 1, and

per 22.

r In operation, the barrel 8 is first thoroughly heated by causing current to traand the barrel 8, together with the shaft 36, is then caused to revolve, the relative. direction of rotation being determined by the direction of pitch of the helical grooves on the members 35-35. The charge slowly passes down through the barrel 8 and is thoroughly mixed and ground by. the members 35-35, its rapidity of passage being capable of accurate control bythe speed adjustment of the motor 37, so that a given portion of the charge may be subjected to chemical action for so long a period of time as is deemed necessary.

.In the form 'ofmyinvention shown in .Figs. 5, 6 and 7, a' furnace barrel 40 is employed, said barrelpreferably comprising an outer casing 9 rovided with a heat resistant lining 10, which, in turn, is providedwith a The chargei'lc'ollecting in the pocket 28,. may ferrous lining41, preferably composed. of-

anid, eit er 'by1llixiviati0n or by acuum des'ired. The specific process t n' par tiils thecz d i mae fi form's no '1 part of this. inventien an SS rings 42-42.

Acqmbi ned heating, grinding and catalyzstructure is shown within the barrel 9 preferably comprises a plus ral ty. of ring s 44-44, each of which is preferably disposed to bear upon the inner or one of the rings 42-42, respe the y,; g edby'suitable conducting bars 45-45, the

' e 'conductmg bars on Said rings 44-44 are interconnectone side of a given ring 44 preferably being mounted in spaced relation to those on the other side of said ring, as indicated in Figs. 6 and 7. The rings 4242 are separated by insulating spacer members 55-55 in order to prevent shortcircuiting the rings 4444.

The entire structure 4343 may be rotated, as by a motor 46 and electric current from a suitable source may be supplied to one end thereof by a brush 47 and taken from the other end thereof by a brush 48. In order to prevent the shunting of current from said device, it may be mounted in insulating bearings, as indicated at 4949.

In operation, current is first passed beween the brushes 47 and 48, thoroughly heating the entire structure 43. The charge is then permitted to flow from the hopper 22 and passes down slowly through the barrel 40, being continuously mixed and ground by the rings 44 and the bars 45, at the same time being chemically acted upon by said rings and conducting bars which are of ferrous nature and 'of sufficiently high temperature to act effectively as catalytic members. A f ter" traversing the barrel 40, the resultant products are received at 28, as before.

In the apparatus of Fig. 5, I have shown the nitrogen as flowing from a tank 50, it sometimes being desirable to employ substantially pure nitrogen. The excess of nit-rogen may be carried away by a pipe 51 and suitably purified for return to the system.

IVhile I have shown my invention in three of its preferred forms, I desire it to be distinctly understood that I am not restricted thereto but that I may modify any or all of the structures shown in many particulars as by interchanging features thereof and by modifying features of one apparatus in a manner similar to that mentioned for another form of the apparatus.

I desire, therefore, that only such restrictions shall beplaced upon the present invention as are imposed by the prior art or are specifically set forth in the appended claims.

I claim as my inventionf 1. In a furnace for the carrying out of a chemical reaction involving the action of a catalytic agent upon a mass of material, a mixing device for said material formed, in part at least, from said catalytic agent, whereby substantially all portions of said mass are periodically subjected to the action of said catalytic agent. 2. In a furnace for the carrying out of a chemical reaction involving the action of a catalytic agent upon finely divided material, a grinding mechanism having a portion of its vgrinding faces formed of said catalytic agent and arranged to operate upon said treated material.

' 3. In a furnace for the carrying out of a chemical reaction involving the action of iron as a catalytic agent upon a mass of material, a grinding mechanism for said material, a portion of the grinding faces of which are composed of iron. A

5. In a rotatable furnace for the carrying out of a chemical reaction involving the action of a catalytic agent upon a mass of finely divided material, a rotatable body disposed against the inner wall of said furnace, whereby, when said furnace is rotated, a pulverizing action is exerted upon said finely divided material, at least one of the two coactive pulverizing surfaces being faced with said catalytic agent.

(3. In a rotatable furnace for the carrying out of a chemical reaction involvingthe catalytic action of iron upon a mass of finely divided material, a rotatable body disposed against the inner side of the wall of said furnace, whereby, when said furnace is rotated, a pulverizing action is exerted upon said finely divided material, at least one of the two coacting pulverizing surfaces being faced with iron.

7. In a rotatable furnace for the carrying out of a chemical reaction involving the action of a catalytic agent upon a mass of finely divided material, a rotatable body formed of said catalytic agent and disposed against the inner wall of said furnace, whereby, when said furnace is rotated, a pulverizing action is exerted upon said finely divided material and the catalytic agent composing said rotatable body is brought into intimate contact with all por tions of said finely divided mass.

8. In a rotatable furnace for the carrying out of a chemical reaction involving the catalytic action of iron upon a mass-v of finely divided material, a rotatable body of iron disposed against the inner side of the wall of said furnace, whereby, when said furnace is rotated, a pulverizing action is exerted upon said finely divided material and the surface of said iron body is brought into intimate contact with all portions of the charge.

9. In a rotatable furnace for the carrying out of a chemical reaction involving the action of a catalytic agent upon a mass of finely divided material, a rotatable body disposed against. the inner face of the wall of said furnace, whereby, when said furnace is rotated, a pulverizing action is exerted upon said finely divided material, the tracking surface containing an appreciable amount of said catalytic agent.

10. In arotatable furnace for the carrying out of a chemical reaction involving the catalytic action of iron upon a mass of finely divided material, a rotatable body disposed against the inner side of the wall of said' the tracking surface includingan appreciable amount of iron.

11. Ina rotatable furnace for e carrying out of a chemicalreaction i volving the action of a catalytic agent upo a mass -of finely divided material, ,a rota ble body formed from said catalytic a ent an dising out of a chemical reaction involving the catalytic action of iron upon a mass of finely appreciable amountof iron.

posed against the inner wall 0 said 'urnace,

whereby, when said furnace is rotated, a pulverizing action is exerted upon said finely dividedmaterial, the tracking surface containing an appreciable amount of said catalytic agent.

12. In a rotatable furnace'for thecarrydivided material, a'rotatable body of iron disposed against the inner side of the wall material," a portion of the grinding faces of of said furnace, whereby, when said-furnace is rotated, a upon said fin y divided material, the material of the tracking surface including an 13.- The combination with a furnace for the production of'cyanid compoundsiof a metal by the action of carbon and nitrogen.

upon a salt of said metal, of .a grinding and mixing mechanism adapted to operate mixing mechanlsm adapted to operate upon the charge and composed, in part at least, 'of

upon the charge and composed, in part, at

least, of a material which operates as a catalyst in assisting the reaction.

14. .The combination with a furnace for the production of cyanid compounds of one.

of the alkali metals by the .action of nitrogen and carbon upon the carbonate of said alkali metal, of a mixing and grinding! mechanism adapted to operate'upon said charge and having a portion of the active pulverizing action isexerted' e 1 vember, 1917.

face thereof composed of iron, whereby the carbon is continually dissolved in said iron and thereupon combines with the nitrogen. 15. In a furnace for the carrying out of a chemical reaction involving the action of nace and in immediate proximity to said mass.

a chemical reaction involving the action of iron as a catalytic agent upon a mass of ma- 16. In a furnace for the carrying outof 1 In a furnace for the carrying out of achemical reaction involving the catalytic- .action of iron upon a mass of finely divided material, a grinding mechanism for said which are composed of iron, and-means for Y passing heating current through saidgrinding mechanism, whereby heat is developed in immediate proximity tothe seat of the chemical reaction. Y Y 18.- The combination with a furnace f0 the production of, cyanid compounds of a metal by the action of carbon and nitrogen.

upon a salt of said metal, of a grinding and amaterial which operates as a catalyst in assisting the reaction, and means for passing heating current through saidgrinding and subscribed my name-this 8th day of No- FREDERICK DARLING ON. 

